之前做過的一款app中涉及到RatingBar控制元件，基本上來說都會要求用圖片來替代，
即使同樣是星星（可能是覺得系統自帶的比較醜吧，不過我覺得還好啊）。
當時就覺得很難去做適配，UI給的圖片沒法去控制寬高，只能使用warp_content來做，
可是這樣會導致控制元件很大，即使是用了maxHeight和minHeight來控制，這只是控制了RatingBar的寬高，
對於RatingBar裡的子控制元件（姑且這麼說吧，有知道的可以告訴我）是沒有效果的。
當時想著自定義來解決，後來專案要求不是那麼嚴格吧，就沒有處理。如果還是那麼做的話會超出螢幕範圍，
沒辦法，只能自己搞定咯。

這是自定義控制元件
 

package com.lg.customstarview;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;

/**
 * 簡單實現星級評選控制元件：內部填充多個ImageView
 * 繼承LinearLayout 設定水平方向
 */
public
 
 class CustomStarView extends LinearLayout {
    private int mImageWidth = 20;  //圖片設定預設的寬度
    private int mImageHeight = 20; //圖片設定預設的高度
    private int mDefaultImageId = R.mipmap.ic_launcher;
    private int mClickImageId = R.mipmap.ic_launcher;
    private int mMargin = 5;   //圖片之間預設的margin
    private int
 
 mStarNum = 5;  //星星預設的個數
    private int mStarChoose = 3;  //預設預設是三顆星
    private boolean isClick = true;

    private OnStarItemClickListener mStarItemClickListener;

    public CustomStarView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initData(context, attrs);
    }

    public CustomStarView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initData(context, attrs);
    }

    /**
     * 初始化資料
     *
     * @param context
     * @param attrs
     */
    private void initData(Context context, AttributeSet attrs) {
        this.setOrientation(HORIZONTAL);  //設定水平
        TypedArray a = context.getTheme().obtainStyledAttributes(attrs,
                R.styleable.StarView, 0, 0);
        int n = a.getIndexCount();

        for (int i = 0; i < n; i++) {
            int attr = a.getIndex(i);
            switch (attr) {
                case R.styleable.StarView_mImageWidth:
                    mImageWidth = (int) a.getDimension(attr, mImageWidth);
                    break;
                case R.styleable.StarView_mImageHeight:
                    mImageHeight = (int) a.getDimension(attr, mImageHeight);
                    break;
                case R.styleable.StarView_mDefaultImageId:
                    mDefaultImageId = a.getResourceId(attr, mDefaultImageId);
                    break;
                case R.styleable.StarView_mClickImageId:
                    mClickImageId = a.getResourceId(attr, mClickImageId);
                    break;
                case R.styleable.StarView_mMargin:
                    mMargin = (int) a.getDimension(attr, mMargin);
                    break;
                case R.styleable.StarView_mStarNum:
                    mStarNum = a.getInt(attr, mStarNum);
                    break;
                case R.styleable.StarView_mStarChoose:
                    mStarChoose = a.getInt(attr, mStarChoose);
                    break;
            }
        }
        a.recycle();

    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        setStarNum(mStarNum);  //設定個數
    }

    /**
     * 設定星星數量
     * 呼叫該方法可以手動設定星星數量
     * @param number
     */
    public void setStarNum(int number) {
//        if (number <= 0) {
//            try {
//                throw new Exception("設定的資料不能小於等於零");
//            } catch (Exception e) {
//                e.printStackTrace();
//            }
//        }
        this.removeAllViews(); //清空所有view
        if(number == 0){
            for (int i = 0; i < 5; i++) {
                ImageView imageView = new ImageView(getContext());
                final LayoutParams layoutParams = new LayoutParams(mImageWidth, mImageHeight);
                layoutParams.leftMargin = mMargin;
                layoutParams.rightMargin = mMargin;
                imageView.setLayoutParams(layoutParams);
                this.addView(imageView);
                imageView.setImageResource(mDefaultImageId);
//                setStarOnClick(imageView, i);
            }
        }else {
            for (int i = 0; i < number; i++) {
                ImageView imageView = new ImageView(getContext());
                final LayoutParams layoutParams = new LayoutParams(mImageWidth, mImageHeight);
                layoutParams.leftMargin = mMargin;
                layoutParams.rightMargin = mMargin;
                imageView.setLayoutParams(layoutParams);
                this.addView(imageView);
                imageView.setImageResource(mDefaultImageId);
//                setStarOnClick(imageView, i);
            }
            setCurrentChoose(mStarChoose);  //設定當前選擇
        }
    }


    /**
     * 設定點選事件
     *
     * @param imageView
     * @param i
     */
    private void setStarOnClick(final ImageView imageView, final int i) {
        if (imageView != null) {
            imageView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View view) {
                    resetDefaultImage();
                    setCurrentChoose(i+1);
                    if (mStarItemClickListener != null) {
                        mStarItemClickListener.onItemClick(imageView, i);
                    }
                }
            });
        }
    }

    /**
     * 設定當前選擇
     *
     * @param index
     */
    private void setCurrentChoose(int index) {
        if(isClick){
            for (int i = 0; i < index; i++) {
                ImageView imageView = (ImageView) getChildAt(i);
                imageView.setImageResource(mClickImageId);
            }
        }
    }

    /**
     * 重置預設為預設的圖片
     */
    private void resetDefaultImage() {
        int cNum = getChildCount();
        for (int i = 0; i < cNum; i++) {
            ImageView imageView = (ImageView) getChildAt(i);
            imageView.setImageResource(mDefaultImageId);
        }
    }

    public int getImageWidth() {
        return mImageWidth;
    }

    public void setImageWidth(int mImageWidht) {
        this.mImageWidth = mImageWidht;
    }

    public int getImageHeight() {
        return mImageHeight;
    }

    public void setImageHeight(int mImageHeight) {
        this.mImageHeight = mImageHeight;
    }

    public int getDefaultImageId() {
        return mDefaultImageId;
    }

    public void setDefaultImageId(int resouceId) {
        this.mDefaultImageId = mDefaultImageId;
    }

    public int getClickImageId() {
        return mClickImageId;
    }

    public void setClickImageId(int mClickImageId) {
        this.mClickImageId = mClickImageId;
    }

    public OnStarItemClickListener getStarItemClickListener() {
        return mStarItemClickListener;
    }

    public void setmStarItemClickListener(OnStarItemClickListener mStarItemClickListener) {
        this.mStarItemClickListener = mStarItemClickListener;
    }

    /**
     * 星星點選事件
     */
    public interface OnStarItemClickListener {
        public void onItemClick(View view, int pos);
    }
}`

自定義空間設計到的style，放在styles目錄下即可

<!--自定星級控制元件-->
    <declare-styleable name="StarView">
        <attr name="mImageWidth" format="dimension"/>
        <attr name="mImageHeight" format="dimension" />
        <attr name="mDefaultImageId" format="reference" />
        <attr name="mClickImageId" format="reference" />
        <attr name="mMargin" format="dimension" />
        <attr name="mStarNum" format="integer" />
        <attr name="mStarChoose" format="integer" />
    </declare-styleable>

     佈局檔案在這裡

    <com.lg.customstarview.CustomStarView
        android:layout_alignParentRight="true"
        android:layout_marginLeft="5dp"
        android:layout_marginRight="10dp"
        android:id="@+id/start_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        fresco:mClickImageId="@drawable/medal_selected"
        fresco:mDefaultImageId="@drawable/medal"
        fresco:mImageHeight="20dp"
        fresco:mImageWidth="20dp"
        fresco:mMargin="2dp"
        fresco:mStarChoose="3"
        fresco:mStarNum="5" />